Dolomite after calcite (?) (w. mimetite)

TSNB795
Specimen
Melville, P.Olson, D.K.
Exhibit 1. Dolomite after calcite (?) (w. mimetite); 108 mm.
Exhibit 1. Dolomite after calcite (?) (w. mimetite); 108 mm.
Image Credit: Malcolm Southwood
Exhibit 2. Dolomite after calcite (?) (w. mimetite); 108 mm.
Exhibit 2. Dolomite after calcite (?) (w. mimetite); 108 mm.
Image Credit: Malcolm Southwood
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Specimen Title

Dolomite after calcite (?) (w. mimetite)

Associated Minerals

mimetite

Principal Mineral

Dolomite

Precursor Mineral (Uncertain)

Calcite

Size

Cabinet; 108mm

Location in the Mine

Undetermined

Provenance

Olson, D.K.; Melville, P.

Collection

Southwood, M.; MS2023.013

Entry Number

Specimen; TSNB795

Description

A dolomite epimorph that appears to have developed over a botryoidal surface of an unidentified precursor mineral, probably calcite (?). The distal (convex) surface is pale salmon-pink in colour and consists of a gently mammilated surface that displays a weak chatoyance due to the alignment of the crystallites from which it is composed. The proximal (concave) surface (Exhibit 2) is richly invested with radiating sprays of tiny off-white mimetite crystals (XRD confirmed; Paul Carr, University of Wollongong, 2024).

The specimen was formerly in the collection of Paul Melville (Australia) who purchased it from Don Olson. There is no information on earlier provenance and the location in the mine is not recorded.